Comparison of LASIK Translate

7/28/2019 Comparison of LASIK Translate

1/28

1

Comparison of LASIK and Photorefractive Keratectomy for Myopia From 10.00 to 18.00

Diopters 10 Years After Surgery

Mohamad Rosman, MD, FRCSEd, FAMS; Jorge L. Ali, MD, PhD; Dolores Ortiz, PhD; Juan J.

Perez-Santonja, MD

ABSTRACT

PURPOSE: To compare the long-term outcomes of LASIK and photorefractive keratectomy

(PRK) for high myopia ( - 10.00 diopters [D]).

METHODS: This retrospective study included eyes with high myopia that underwent PRK (51

eyes) and LASIK (141 eyes) at the Instituto Oftalmologico de Alicante, Spain, and returned for

10-year follow-up.

RESULTS: Ten years after surgery, 45.5% of eyes in the LASIK group achieved uncorrected

visual acuity (UCVA) of 20/40 or better compared to 31.3% in the PRK group. Rerata efficacy

indices after 10 years in both groups were similar (0.87 in the LASIK group and 0.82 in the PRK

group, P=.51). Twenty-one (41%) eyes in the PRK group were within 1.00 D whereas 60

(42.5%) eyes from the LASIK group were within 1.00 D 10 years after surgery. Six (14%)

eyes from the PRK group lost 2 or more lines of BSCVA compared to 7 (6%) eyes from the

LASIK group.

CONCLUSIONS: LASIK and PRK have been shown to have similar visual acuity efficacy in the

treatment of eyes with high myopia in the long-term, with LASIK having superior visual acuity

effi cacy and safety over PRK within the first 2 years after surgery. However, treatment of

myopia - 10.00 D by LASIK is no longer routinely advocated whereas the treatment of high

myopia by PRK is no longer performed due to potential complications associated with the

treatment. Haze in postoperative PRK eyes was a signifi cant long-term problem in our study.


2/28

2

Prior to the introduction of LASIK in 1991, photorefractive keratectomy (PRK) was the main

surgical procedure for the correction of myopia, including high myopia (myopia - 10.00

diopters [D]). Currently, LASIK is the predominant refractive surgery used for the correction of

myopia1 and is preferred over PRK because it causes much less discomfort postoperatively and

has an almost negligible risk of haze.2 Furthermore, PRK is generally reserved for myopia of < -

6.00 D because of the higher risk of haze after PRK for eyes with > - 6.00 D.3

Numerous studies have shown that both LASIK and PRK are efficacious, safe, and predictable in

correcting myopia. Studies have also shown that both procedures are less effective and

predictable when used to treat eyes with myopia > - 10.00 D.4-16 However, most studies

evaluating the efficacy, safety, and predictability of either LASIK or PRK in the treatment of

high myopia have a maximum follow-up period of 2 years. Two separate 10-year studies by Ali

et al showed that LASIK was effective and safe in treating myopia > - 10.00 D17 and PRK was

effective and safe in treating myopia > - 6.00 D.18

Although many studies compare the outcomes of LASIK versus PRK, most compare eyes with

myopia of > - 10.00 D.2,19-29 Steinert and Hersh30 compared the outcomes of LASIK versus

PRK in the treatment of myopia up to - 12.00 D, Hersh et al31,32 evaluated the outcomes of the

two procedures in myopia up to - 15.00 D, and Pallikaris and Siganos33 compared the outcomes

of LASIK versus PRK in eyes with myopia from - 10.62 to - 25.87 D. However, these studies

only have a maximum follow-up of 12 months.

Photorefractive keratectomy is currently no longer performed for myopia > - 10.00 D and is

recommended mainly for myopia < - 6.00 D. However, the knowledge and comparison of the

long-term effects and refractive outcomes of PRK and LASIK when used at the extreme limits of

the cornea may provide valuable information for the future. No study in the literature currently

compares the long-term refractive outcomes of LASIK and PRK in the treatment of high myopia.

Thus, the aim of this study is to present the 10-year refractive outcomes of LASIK versus PRK in

the treatment of myopia of - 10.00 D in our center.


3/28

3

PATIENTS AND METHODS

PATIENT POPULATION

A total of 4800 charts of eyes that underwent PRK or LASIK between April 1992 and December

1995 at the Instituto Oftalmolgico de Alicante, Spain, were reviewed. Our database was

compiled including 509 eyes of 356 patients treated with myopic PRK and 294 eyes of 178

patients treated with myopic LASIK that returned for follow-up at 3 months and 1, 2, 5, and 10

years after the initial procedure, either spontaneously or after telephone calls (particularly at 10

years). From the data above, we included all eyes that underwent PRK with a preoperative

spherical equivalent refraction - 10.00 D. The maximum preoperative spherical equivalent

refraction of an eye that underwent PRK was - 17.75 D. We subsequently included all eyes (from

the patients who returned for 10-year follow-up) within the preoperative range of - 10.00 to -

17.75 D that underwent LASIK for comparison with PRK.

A total of 51 eyes with high myopia that underwent PRK and 141 eyes with high myopia that

underwent LASIK were included in this study. Rerata age and gender proportions of both the

PRK and LASIK groups were similar (Table). Rerata preoperative manifest refraction spherical

equivalent (MRSE) of the PRK group was - 12.44 D (range: - 10.25 to - 17.75 D) and the LASIK

group was - 12.81 D (range: - 10.13 to - 17.75 D).

Inclusion criteria for LASIK and PRK were similar and included no contact lens wear 4 weeks

before surgery; stable refractive error for at least 6 months before surgery; normal peripheral

retina or treated with photocoagulation when necessary; no previous ocular surgery, corneal

diseases, glaucoma, or history of ocular trauma.

Exclusion criteria for LASIK and PRK were keratoconus or keratoconus suspect as evidenced by

corneal topography, active ocular or systemic disease likely to affect corneal wound healing,

pregnancy, and nursing mothers. Part of the data on the patients reported here have been

previously used in former publications,17,18


4/28

4

as they originate from the same database. However, those patients who fulfi lled the selection

criteria for the present study do not all coincide with those included in previous reports as

different selection criteria were used.

SURGICAL TECHNIQUES

LASIK. The day before surgery, diclofenac sodium 0.1% eye drops (Voltaren; Novartis AG,

Basel, Switzerland) and trimethoprim and polymyxin B eye drops (Oftalmotrim; Cusi,

Barcelona, Spain) were instilled. The procedure was done using topical anesthesia of

oxybuprocaine 0.4%. All surgeries were performed by two surgeons (J.L.A., J.J.P.S.) using the

same technique and protocol. An 8.5-mm diameter nasally hinged anterior corneal flap was

created using the Automated Corneal Shaper (ACS; Chiron Vision, Irvine, Calif) microkeratome

with either a 130- or 160-m head in every patient.

A 193-nm VISX 20/20 excimer laser (VISX Inc, Santa Clara, Calif) was used. Calibration was

done at the beginning of each surgical session. During surgery, patients were instructed to fi xate

on the lasers heliumneon fixation light. Ablation was achieved using a beam with fluence of 160

mJ/cm2 at an ablation rate of 5 Hz. A 5.0-, 5.5-, and 6.0-mm diameter multiple zone technique

was used. Astigmatism was corrected by sequential ablation with an area of 6.0-4.5 mm.

Emmetropia was attempted in all cases.

Postoperatively, tobramycin (Tobrex; Alcon Laboratories Inc, Ft Worth, Tex) and diclofenac

0.1% eye drops (Novartis AG) were used. Dexamethasone 0.1% was used four times a day

during the first week. Sub-sequently, fluorometholone 0.25% eye drops were applied four times

daily for 4 weeks based on the refraction and intraocular pressure. The steroid dose was tapered

gradually (three times and two times daily for 2 weeks each).

PRK. Surgery was performed using topical anesthesia of oxybuprocaine hydrochloride 0.4% and

tetracaine hydrochloride. The day before surgery, diclofenac sodium 0.1% drops (Voltaren,

Novartis AG) and trimethoprim and polymyxin B eye drops (Oftalmotfrim,

Cusi) were instilled.

A 193-nm VISX 20/20 excimer laser (software version 3.2; VISX Inc) was used. Calibration was

carried out at the beginning of each surgical session. The eyelids were retracted with a speculum.

During surgery, patients fixated on the lasers helium-neon fixation light. Deepithelialization was

performed by laser according to a previously described technique.34 Ablation was achieved


5/28

5

using a beam with a fluence of 160 mJ/cm2 at an ablation rate of 5 Hz. A 4.5-, 5.0-, and 6.0-mm

diameter multiple zone technique was used to correct for high myopia. Astigmatism was

corrected by sequential ablation with an area of 6.0-4.5 mm. Emmetropia was attempted in all

cases. All procedures were performed by two surgeons (J.L.A., J.J.P.S.) using the same

technique and protocol.

After surgery, tobramycin ointment (Tobrex, Alcon Laboratories) was administered before

patching. The antibiotic ointment was used three times daily until complete reepithelialization.

Fluorometholone 0.25% drops (FML Forte; Allergan Inc, Irvine, Calif) were prescribed four

times daily for 1 month and then tapered by one drop over the following 3 months until

cessation. Haze or regression was treated with topical corticosteroids when needed. Mitomycin C

was not used in any case during or after surgery.

CLINICAL EXAMINATIONS

Patients were evaluated preoperatively, 1 day, 1 week, 1 and 3 months, and 1, 2, 5, and 10 years

after LASIK or PRK. However, for the purpose of this study, only data from the preoperative, 3-

month, and 1-, 2-, 5-, and 10-year follow-up were analyzed.

Clinical examinations during follow-up included measurement of manifest refraction,

cycloplegic refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual

acuity (BSCVA). Slit-lamp microscopy, dilated fundus examination, applanation tonometry,

corneal topography, and evaluation of corneal haze were also performed during follow-up.

Corneal thickness measurements were not routinely taken during follow-up.

Corneal haze was measured at the slit lamp and was graded on a scale of 0 to 4, according to a

clinical grading system, which we described previously.18 Patients were examined and evaluated

by independent examiners at each follow-up. Data obtained at the end of 10 years were evaluated

and analyzed using the format for reporting refractive surgical data.35,36 Efficacy index was

defi ned as (postoperative UCVA/preoperative BSCVA) and the safety index was defi ned as

(postoperative BSCVA/preoperative BSCVA).

STATISTICAL ANALYSIS

Statistical analysis was performed using SPSS for Windows, version 11.5 (SPSS Inc, Chicago,

Ill). The differences between the two groups in categorical clinical outcomes were assessed using


6/28

6

chi-square tests. Quantitative outcomes were analyzed using two-sample t test when normality

(checked using Kolmogorov - Smirnov test coupled with histograms) and homogeneity of

variance assumptions were satisfied; otherwise the non-parametric equivalent Mann-Whitney U

test was applied. Statistical signifi cance was set atP-.05.

RESULTS

VISUAL ACUITY EFFICACY

Preoperatively, 73% of eyes (103/141) in the LASIK group had BSCVA 20/40 or better

compared to 58.8% of eyes (30/51) in the PRK group (P=.045). Rerata UCVA in the LASIK

group was higher 3 months (0.46-0.18 vs 0.31-0.20, P-.01), 1 year (0.51-0.18 vs 0.38-0.19, P-

.01), and 2 years (0.53-0.18 vs 0.41-0.19, P-.01) after surgery compared to the PRK group (Fig

1). Rerata UCVA in the LASIK group was also better than the PRK group at 5 and 10 years

postoperatively, but the difference was not statistically significant.

Three months after surgery, the percentage of eyes in the LASIK group with UCVA of 20/40 or

better was 49.6% (69/139) compared to 23.5% (12/51) in the PRKgroup (P-.01). The percentage

of eyes with UCVA of 20/40 or better was higher in the LASIK group compared to the PRK

group throughout all follow-up. The difference was statistically signifi cant at 3 months, 1

year, and 2 years after surgery (Fig 2).

Rerata efficacy index of the PRK group was 0.65-0.38 3 months after surgery compared to 0.85-

0.35 in the LASIK group (P-.01). The rerata efficacy indices of the PRK group improved to

0.80-0.38 1 year after surgery and 0.88-0.34 2 years after surgery (Fig 3). However, the rerata

efficacy indices of the PRK group remained statistically lower compared to the LASIK group 1

year postoperatively. The rerata efficacy indices of the PRK group continued to improve and at 5

years after surgery, the rerata efficacy index of the PRK group was 0.94-0.40 and 0.94-0.42 for

the LASIK group (P=.95). No statistical difference was noted in the rerata efficacy indices of

both groups 10 years after surgery (0.82-0.51 in the PRK group versus 0.87-0.50 in the LASIK

group,P=.51).

STABILITY AND RETREATMENTS

The rerata MRSE of the PRK group showed an undercorrection of -0.91-1.76 D 3 months after

surgery, which improved to -0.51-1.38 D 1 year postoperatively (Fig 4). The rerata MRSE in the


7/28

7

PRK group was -1.81-1.79 D 10 years after surgery. The stability graph of the LASIK group

shows an initial overcorrection of 0.31-1.86 D followed by regression (see Fig 4). The rerata

MRSE 10 years after surgery was -1.48-1.99 D. The rerata total regression over 10 years (from

1- to 10- year follow-up) was 1.28-1.78 D in the PRK group and 1.49-2.17 D in the LASIK

group (P=.54).

Retreatment data were available for 44 PRK eyes. Thirteen (29.5%) eyes in the PRK group

underwent one retreatment procedure and 9 (20.5%) eyes underwent two retreatment procedures

during the 10-year follow-up period. In the LASIK group, 37 (26.2%) eyes underwent one

retreatment procedure and 2 (1.4%) eyes required two retreatment procedures. For PRK, 10 of 13

eyes underwent retreatment between 3-month and 1-year follow-up, 2 eyes between 1- and 2-

year follow-up, and 1 eye between 2- and 5-year follow-up. In the LASIK group, 25 of 37 eyes

underwent retreatment between 3-month and 1-year follow-up, 6 eyes between 1- and 2-year

follow-up, and 6 eyes between 5- and 10-year follow-up. All PRK eyes underwent retreatment

with PRK and all LASIK eyes underwent retreatment with LASIK.

PREDICTABILITY OF REFRACTIVE OUTCOMES

One year after surgery, 35 (68.6%) eyes in the PRK group were within -1.00 D of attempted

correction whereas 90 (63.8%) eyes from the LASIK group were within -1.00 D. Fifty-nine

percent of eyes (30 eyes) in the PRK group were within -1.00 D of emmetropia compared to

64.5% (91 eyes) in the LASIK group 2 years after surgery (Fig 5A). These figures decreased to

41% (21 eyes) in the PRK group and 42.5% (60 eyes) in the LASIK group 10 years after surgery

(Fig 5B). The proportions of eyes with MRSE of -1.00 D or worse in both groups were higher 10

years after surgery compared to 2 years after surgery. Thirty-three percent of eyes (17 eyes) in

the PRK group had MRSE of -1.00 D or worse 2 years after surgery compared to 57% of eyes

(29 eyes) 10 years after surgery. In the LASIK group, 15% of eyes (22 eyes) had MRSE of -1.00

D or worse 2 years after surgery compared to 50% of eyes (71 eyes) 10 years after surgery.

SAFETY AND COMPLICATIONS

The change in lines of BSCVA 10 years after surgery is summarized in Figure 6. These data

were available for 43 PRK eyes and 117 LASIK eyes. Six (14%) eyes from the PRK group lost 2


8/28

8

or more lines of BSCVA compared to 7 (6%) eyes from the LASIK group. Four eyes from the

PRK group lost 2 or more lines of BSCVA due to choroidal neovascular membrane formation

and the loss in the other 2 eyes was due to the presence of haze. Two eyes from the LASIK

group lost 2 or more lines of BSCVA due to choroidal neovascular membrane formation, 1 eye

to retinal detachment, and 4 eyes to cataract formation. There were no cases of cornea ectasia in

either the PRK or LASIK group.

Eighteen (35.3%) eyes that underwent PRK had at least grade 1 haze 3 months after surgery. At

2 years postoperatively, 11 (21.6%) eyes were observed to have grade 1 haze. At 10-year follow-

up, 6 (11.8%) eyes were noted to have grade 1 haze. One (16.7%) of these 6 eyes underwent two

retreatments and 1 (16.7%) eye underwent only one retreatment. No eye that underwent LASIK

was noted to have haze during 10-year follow-up.

The rerata safety index was calculated after excluding all eyes with cataracts or retinal pathology

(PRK: 2 cataracts, 4 choroidal neovascular membrane, and 1 retinal detachment; LASIK: 18

cataracts, 5 choroidal neovascular membrane, and 5 retinal detachments). The rerata safety index

of the PRK group was lower than the LASIK group at 3 months after surgery (0.93-0.37 vs 1.11-

0.35,P-.01). The rerata safety indices of the LASIK group remained higher than the PRK group

at 1-, 2-, 5-, and 10-year follow-up. However, the differences in rerata safety indices were not

statistically signifi cant (Fig 7).

DISCUSSION

Our study compared the 10-year refractive outcomes of eyes with high myopia ( - 10.00 D),

which had undergone LASIK or PRK at our center. Today, PRK is no longer performed for high

myopia. Phakic intraocular lenses (IOLs) are also preferred over LASIK in the treatment of high

myopia and are a safer option especially if the cornea is relatively thin. Hence, our data

comparing the long-term effects of PRK and LASIK when used at the extreme limits of excimer

laser will be impossible to obtain today. Although data in the literature compare eyes that

underwent LASIK versus PRK, the number of studies comparing eyes with high myopia is

lacking and the few such studies have follow-up periods of 12 months or less.30,32,33 A meta-

analysis by Shortt et al37 reported that LASIK has superior efficacy and safety compared to

PRK; however, this meta analysis involved randomized controlled studies that evaluated eyes

with myopia of up to - 8.00 D.


9/28

9

The visual acuity efficacy of PRK in eyes with high myopia in our study is lower than LASIK,

especially in the first 2 years after surgery. This is reflected in the lower rerata UCVA,

proportion of eyes with UCVA of 20/40 or better, and the rerata effi cacy index for all follow-up

examinations. Helmy et al,29 in a study comparing eyes with preoperative myopia of -6.00 to -

10.00 D that had undergone PRK and LASIK, also reported superior visual acuity effi cacy for

LASIK compared to PRK. One possible explanation for the inferior results of PRK is the high

incidence of haze among eyes with PRK in our study. The proportion of eyes with haze in our

study decreased with time. However, at 10-year follow-up 11.8% (6/51) of eyes still had grade 1

haze, with 2 eyes having lost 2 or more lines of BSCVA.

Both the LASIK and PRK groups showed statistically similar regression over the 10-year follow-

up period. At 10-year follow-up, the LASIK group demonstrated a rerata change of -1.49 D

compared to the fi rst year refraction whereas the PRK group demonstrated a rerata change of -

1.28 D. An improvement in rerata MRSE towards emmetropia was noted at 1-year follow-up

compared to 3-month follow-up in the PRK group. This is attributed to the retreatment

procedures, which were mostly performed within the first year after PRK. The refractive

predictability of both the LASIK and PRK groups appears similar at 10-year follow-up, with

41% (21/51) of eyes in the PRK group and 42.5% (60/141) of eyes in the LASIK group within -

1.00 D of emmetropia. However, more eyes in the PRK group required retreatment and more

eyes in the PRK group required multiple retreatments, suggesting that PRK may have a lower

long-term refractive predictability in eyes with high myopia compared to LASIK.

The long-term complications of PRK and LASIK in the treatment of high myopia have been well

described in other studies.17,18 In our study, a higher percentage of eyes in the PRK group

(14%, 6 eyes) lost more than 2 lines of BSCVA compared to the LASIK group (6%, 7 eyes).

However, the causes of the reduction in BSCVA in most cases are likely to be associated with

high myopia and age rather than with the procedures alone, ie, choroidal neovascular membrane

formation, retinal detachment, and cataracts. 38 - 41 In our analysis of the rerata safety indices,

after excluding cases with retinal pathology or cataracts, we observed no statistical difference in

the rerata safety indices between the LASIK and PRK groups.

The development of haze in postoperative PRK eyes is a direct complication of PRK, and the

incidence and severity is worse for eyes with high myopia. In our study, 2 (4.6%) eyes that

underwent PRK lost 2 or more lines of BSCVA due to haze and another 4 (9.4%) eyes were also


10/28

10

observed to have grade 1 haze 10 years after surgery. This may be a compelling reason not to

perform PRK in eyes with high myopia. Haze is a potential adverse effect seen in eyes that have

undergone PRK. It can occur in any postoperative PRK eye but is more common among eyes

with myopia - 6.00 D. It is also more severe in higher myopia.5 Studies have reported up to 85%

haze after 24 months in eyes with myopia of - 6.00 to - 10.00 D that have undergone PRK and in

8.6% of eyes with preoperative myopia - 6.00 D 10 years after PRK.3,18 In our study, we also

noted a reduction in the number of eyes that were observed to have haze with time. Eighteen

(35.3%) eyes were noted to have haze of at least grade 1 compared to 6 (11.8%) eyes at 10-year

follow-up. This was consistent with other studies that showed similar reduction in the incidence

of haze with time.18 Although it has been suggested that the use of mitomycin C during PRK

may decrease the incidence and severity of haze,42,43 more studies are needed to confirm this

finding.

High myopia is a risk factor for postoperative LASIK corneal ectasia.44 Although no eyes in our

study lost two or more lines of BSCVA due to corneal ectasia, meticulous preoperative patient

selection is required to reduce the risk of this complication. Treatment of high myopia requires a

greater amount of stromal ablation to correct the refractive error, resulting in a thinner residual

stromal bed, which may increase the risk of postoperative LASIK ectasia. Although the safe

residual stromal bed thickness is debatable, most refractive surgeons agree that a residual stromal

bed of at least 250 m will reduce the risk of postoperative LASIKectasia. Thus, it is important

to measure the preoperative corneal thickness and to calculate the residual corneal thickness.

This is a retrospective study with its associated problems, for example, missing data for some

follow up examinations, inter-observer bias, etc. One important limitation of our study is that due

to the long-term nature of our study and the rapid advancement of refractive surgery technology,

the technology and techniques used in our study are no longer in use currently. Changes in

technology and techniques since the study period are likely to alter our findings. However, as

PRK is not routinely used to treat high myopia currently, a similar study would be impossible to

conduct. With the introduction of newer generation phakic IOLs, which are safer, LASIK is also

no longer routinely used to treat high myopia. Another important limitation is that we only have

data on patients who returned for follow-up (approximately 15% to 20%). We do not have

information on why patients did not return for follow-up. They may have had complications such

as corneal ectasia or haze or may just be satisfied patients who did not want further follow-up.


11/28

11

Laser in situ keratomileusis and PRK have been shown to have similar visual acuity effi cacy in

the treatment of eyes with myopia - 10.00 D in the long-term but visual rehabilitation in

postoperative PRK eyes appears to take longer compared to LASIK. Laser in situ keratomileusis

has also been shown to have superior visual acuity efficacy and safety over PRK in the first 2

years after surgery. However, treatment of myopia - 10.00 D by LASIK is no longer routinely

advocated whereas PRK is no longer performed due to potential complications associated with

the treatment of high myopia in both procedures. Both procedures are associated with signifi cant

regression in the longterm with a higher percentage of eyes that underwent PRK requiring at

least one retreatment procedure during the 10-year follow-up. Haze in postoperative PRK eyes

with high myopia was a signifi cant long-term problem and is an important consideration to

preclude performing PRK on eyes with high myopia.


12/28

12

Comparison of LASIK and Photorefractive Keratectomy for Myopia From 10.00 to 18.00

Diopters 10 Years After Surgery

Mohamad Rosman, MD, FRCSEd, FAMS; Jorge L. Ali, MD, PhD; Dolores Ortiz, PhD; Juan J.

Perez-Santonja, MDABSTRACTABSTRAK

TUJUAN: Untuk membandingkan hasil jangka panjang dari LASIK dan keratectomy

photorefractive (PRK) untuk miopia tinggi ( - 10.00 dioptri [D]).

METODE: Penelitian retrospektif termasuk mata dengan miopia tinggi yang menjalani PRK (51

mata) dan LASIK (141 mata) di Oftalmologico Instituto de Alicante, Spanyol, dan kembali

untuk 10 tahun tindak lanjut.

HASIL: Sepuluh tahun setelah operasi, 45,5% dari mata di grup LASIK dicapai tidak dikoreksi

ketajaman visual (UCVA) dari 20/40 atau lebih baik dibandingkan dengan 31,3% pada

kelompok PRK.Rerata Indeks Kepercayaan setelah 10 tahun di kedua kelompok adalah sama

(0,87 pada kelompok LASIK dan 0,82 pada kelompok PRK, P=. 51). Dua puluh satu (41%)

mata di kelompok PRK itu dalam 1,00 D sedangkan 60 (42,5%) dari kelompok mata LASIK

itu dalam waktu 1,00 tahun D 10 setelah operasi. Enam (14%) dari kelompok mata PRK

kehilangan 2 atau lebih baris BSCVA dibandingkan 7 (6%) dari kelompok mata LASIK.

KESIMPULAN: LASIK dan PRK telah terbukti memiliki kemanjuran ketajaman visual yang

sama dalam pengobatan mata dengan miopia tinggi dalam jangka panjang, dengan LASIK

memiliki ketajaman visual yang superior efisiensi dan keamanan atas PRK dalam 2 tahun

pertama setelah operasi.Namun, perawatan miopia - 10.00 D oleh LASIK tidak lagi secara

rutin menganjurkan sedangkan pengobatan miopia tinggi oleh PRK tidak lagi dilakukan karena

komplikasi potensial terkait dengan pengobatan.Kabut di mata PRK pascaoperasi adalah tidak

signifikan masalah jangka panjang dalam penelitian kami.

Sebelum pengenalan LASIK pada tahun 1991, keratectomy photorefractive (PRK) adalah

prosedur pembedahan utama untuk koreksi miopia, termasuk miopia tinggi ( miopia - 10.00

dioptri [D]).Saat ini, LASIK adalah pembedahan yang dominan bias digunakan untuk koreksi

myopia1 dan lebih disukai daripada PRK karena menyebabkan kurang ketidaknyamanan pasca

operasi dan memiliki risiko hampir diabaikan haze.2 Selanjutnya, PRK biasanya disediakan

untuk miopia dari -

D.3 6,00


13/28

13

Sejumlah penelitian telah menunjukkan bahwa kedua LASIK dan PRK yang manjur, aman, dan

dapat diprediksi dalam mengoreksi miopia.Studi juga menunjukkan bahwa kedua prosedur yang

kurang efektif dan dapat diprediksi bila digunakan untuk mengobati mata dengan> miopia -

10.00 D.4-16 Namun demikian, kebanyakan studi mengevaluasi kemanjuran, keamanan, dan

prediktabilitas baik LASIK atau PRK dalam pengobatan miopia tinggi memiliki tindak lanjut

jangka waktu maksimum 2 tahun.Dua penelitian 10 tahun terpisah oleh Ali et al menunjukkan

bahwa LASIK efektif dan aman dalam mengobati> miopia - 10.00 D17 dan PRK efektif dan

aman dalam mengobati> miopia - 6,00 D.18

Meskipun banyak studi membandingkan hasil LASIK versus PRK, paling membandingkan mata

dengan miopia dari> - 10.00 ,19-29 D.2 Steinert dan Hersh30 membandingkan hasil LASIK

versus PRK dalam pengobatan miopia sampai dengan - 12.00 D, et Hersh al31, 32 mengevaluasi

hasil dari dua prosedur dalam miopia sampai dengan - 15.00 D, dan Pallikaris dan Siganos33

membandingkan hasil LASIK versus PRK di mata dengan miopia dari - ke 10,62 - 25,87 D.

Namun, penelitian ini hanya memiliki maksimum tindak lanjut dari 12 bulan.

Photorefractive keratectomy saat tidak lagi dilakukan untuk> miopia - 10.00 D dan dianjurkan

terutama untuk


14/28

14

maksimum yang menjalani PRK itu - 17,75 D. Kita kemudian termasuk semua mata (dari pasien

yang kembali selama 10 tahun tindak lanjut) dalam rentang pra operasi dari - 10.00 ke - 17,75 D

yang menjalani LASIK untuk perbandingan dengan PRK.

Sebanyak 51 mata dengan miopia tinggi yang menjalani PRK dan 141 mata dengan miopia

tinggi yang menjalani LASIK dilibatkan dalam penelitian ini.Usia rata-rata dan proporsi gender

baik dari PRK dan kelompok LASIK adalah sama (Tabel). Berarti setara bola refraksi nyata

preoperative (MRSE) dari kelompok PRK itu - 12,44 D (kisaran: - 10,25 untuk - 17,75 D) dan

kelompok LASIK- 12,81 D (kisaran: - 10,13 untuk - 17,75 D).

Kriteria inklusi untuk LASIK dan PRK adalah sama dan tidak termasuk lensa kontak memakai 4

minggu sebelum operasi; kesalahan bias stabil untuk setidaknya 6 bulan sebelum operasi; retina

perifer normal atau diperlakukan dengan photocoagulation bila perlu, tidak ada operasi mata

sebelumnya, penyakit kornea, glaukoma, atau riwayat trauma mata.

Kriteria Eksklusi untuk LASIK dan PRK adalah keratoconus atau keratoconus tersangka yang

dibuktikan dengan topografi kornea, penyakit mata atau sistemik aktif akan mempengaruhi

penyembuhan luka kornea, kehamilan, dan menyusui. Bagian dari data pada pasien yang

dilaporkan di sini sebelumnya telah digunakan dalam publikasi sebelumnya, 17,18 seperti

mereka berasal dari database sama.Namun, pasien yang memenuhi kriteria seleksi untuk

penelitian ini tidak semua bertepatan dengan yang termasuk dalam laporan sebelumnya sebagai

kriteria seleksi yang berbeda digunakan.

TEKNIK BEDAH

LASIK. Sehari sebelum operasi, tetes mata 0,1% natrium diklofenak (tablet Voltaren retard;

Novartis AG, Basel, Swiss) dan trimetoprim dan tetes mata B polymyxin (Oftalmotrim; Cusi,

Barcelona, Spanyol) telah ditanamkan.Prosedur dilakukan dengan menggunakan anestesi topikal

dari oxybuprocaine 0,4%. Semua operasi dilakukan oleh dua ahli bedah (JLA, JJPS)

menggunakan teknik yang sama dan protokol. Sebuah flap kornea anterior diameter 8,5 pada

daerah nasal diciptakan dengan menggunakan Automated kornea pembentuk (ACS; Chiron Visi,

Irvine, California) microkeratome dengan baik 130 - atau-m kepala 160 orang di setiap pasien.

A-193 nm VISX 20/20 excimer laser (VISX Inc, Santa Clara, California) digunakan. Kalibrasi

dilakukan pada setiap awal sesi bedah.Selama operasi, pasien diperintahkan untuk fiksasi kepala

pada cahaya laser.Ablasi dicapai dengan menggunakan sinar dengan fluence 160 mJ/cm2 pada

tingkat ablasi dari 5 Hz. Sebuah 5.0, 5.5-, dan beberapa mm diameter zona teknik-6,0 digunakan.


15/28

15

Astigmatism was corrected by sequential ablation with an area of 6.0-4.5 mm. Astigmatisma

telah dikoreksi oleh ablasi berurut dengan luas 6,0-4,5 mm. Emmetropia was attempted in all

cases.Emmetropia telah berusaha dalam semua kasus.

Postoperatively, tobramycin (Tobrex; Alcon Laboratories Inc, Ft Worth, Tex) and diclofenac

0.1% eye drops (Novartis AG) were used.Pascaoperasi, tobramisin (Tobrex; Alcon Laboratories

Inc, Ft Worth, Tex) dan diklofenak tetes mata 0,1% (Novartis AG) digunakan.Dexamethasone

0.1% was used four times a day during the first week.Deksametason 0,1% digunakan empat kali

sehari selama minggu pertama.Sub-sequently, fluorometholone 0.25% eye drops were applied

four times daily for 4 weeks based on the refraction and intraocular pressure. Sub-sequently,

fluorometholone tetes mata 0,25% yang diterapkan empat kali setiap hari selama 4 minggu

berdasarkan refraksi dan tekanan intraokular.The steroid dose was tapered gradually (three times

and two times daily for 2 weeks each). Dosis steroid bertahap tapered (tiga kali dan dua kali

sehari selama 2 minggu masing-masing).

PRK. Surgery was performed using topical anesthesia of oxybuprocaine hydrochloride 0.4% and

tetracaine hydrochloride. PRK. Operasi dilakukan dengan anestesi topikal oxybuprocaine

hidroklorida 0,4% dan hidroklorida tetracaine.The day before surgery, diclofenac sodium 0.1%

drops (Voltaren, Novartis AG) and trimethoprim and polymyxin B eye drops (Oftalmotfrim,

Sehari sebelum operasi, natrium diklofenak 0,1% tetes (tablet Voltaren retard, Novartis AG) dan

trimetoprim dan tetes mata B polymyxin (Oftalmotfrim,

Cusi) were instilled.Cusi) yang ditanamkan.

A 193-nm VISX 20/20 excimer laser (software version 3.2; VISX Inc) was used. A-193 nm

VISX 20/20 excimer laser (perangkat lunak versi 3,2; VISX Inc) digunakan. Calibration was

carried out at the beginning of each surgical session.Kalibrasi dilakukan pada setiap awal sesi

bedah.The eyelids were retracted with a speculum.Kelopak mata yang ditarik dengan sebuah

spekulum. During surgery, patients fixated on the laser's helium-neon fixation light. Selama

operasi, pasien yang terpaku pada helium-neon sinar laser fiksasi. Deepithelialization was

performed by laser according to a previously described technique.34 Ablation was achieved

using a beam with a fluence of 160 mJ/cm2 at an ablation rate of 5 Hz. Deepithelialization

dilakukan dengan laser menurut technique.34 ablasi dijelaskan sebelumnya sudah dicapai dengan

menggunakan balok dengan fluence 160 mJ/cm2 pada tingkat ablasi dari 5 Hz.A 4.5-, 5.0-, and

6.0-mm diameter multiple zone technique was used to correct for high myopia. 4,5-A, 5.0, dan


16/28

16

mm diameter beberapa teknik-zona 6,0 digunakan untuk mengoreksi miopia tinggi.Astigmatism

was corrected by sequential ablation with an area of 6.0-4.5 mm.Astigmatisma telah dikoreksi

oleh ablasi berurut dengan luas 6,0-4,5 mm.Emmetropia was attempted in all cases.Emmetropia

telah berusaha dalam semua kasus.All procedures were performed by two surgeons (JLA, JJPS)

using the same technique and protocol. Semua prosedur dilakukan oleh dua ahli bedah (JLA,

JJPS) menggunakan teknik yang sama dan protokol.

After surgery, tobramycin ointment (Tobrex, Alcon Laboratories) was administered before

patching. Setelah operasi, tobramisin salep (Tobrex, Alcon Laboratories) diberikan sebelum

patch. The antibiotic ointment was used three times daily until complete reepithelialization.

Salep antibiotik digunakan tiga kali sehari sampai reepithelialization lengkap.Fluorometholone

0.25% drops (FML Forte; Allergan Inc, Irvine, Calif) were prescribed four times daily for 1

month and then tapered by one drop over the following 3 months until cessation. 0,25% tetes

Fluorometholone (FML Forte; Allergan Inc, Irvine, California) telah ditetapkan empat kali sehari

selama 1 bulan dan kemudian meruncing dengan satu tetes selama 3 bulan berikutnya hingga

penghentian.Haze or regression was treated with topical corticosteroids when needed.Haze atau

regresi diobati dengan kortikosteroid topikal bila diperlukan.Mitomycin C was not used in any

case during or after surgery.Mitomycin C tidak digunakan dalam hal apapun selama atau setelah

operasi.

CLINICAL EXAMINATIONSPemeriksaan KLINIS

Patients were evaluated preoperatively, 1 day, 1 week, 1 and 3 months, and 1, 2, 5, and 10 years

after LASIK or PRK.Pasien dievaluasi sebelum operasi, 1 hari, 1 minggu, 1 dan 3 bulan, dan 1,

2, 5, dan 10 tahun setelah LASIK atau PRK.However, for the purpose of this study, only data

from the preoperative, 3-month, and 1-, 2-, 5-, and 10-year follow-up were analyzed.Namun,

untuk tujuan penelitian ini, data hanya dari pra operasi, 3-bulan, dan 1 -, 2 -, 5 -, dan 10 tahun

tindak lanjut dianalisis.

Clinical examinations during follow-up included measurement of manifest refraction,

cycloplegic refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual

acuity (BSCVA).pemeriksaan klinis selama masa tindak lanjut termasuk pengukuran refraksi

manifest, refraksi cycloplegic, tidak dikoreksi ketajaman visual (UCVA), dan terbaik tontonan-

dikoreksi ketajaman visual (BSCVA). Slit-lamp microscopy, dilated fundus examination,

applanation tonometry, corneal topography, and evaluation of corneal haze were also performed


17/28

17

during follow-up.Celah-lampu mikroskop, melebar pemeriksaan fundus, tonometri applanation,

topografi kornea, dan evaluasi kabut kornea juga dilakukan selama masa tindak lanjut. Corneal

thickness measurements were not routinely taken during follow-up.pengukuran ketebalan

kornea tidak diambil secara rutin selama masa tindak lanjut.

Corneal haze was measured at the slit lamp and was graded on a scale of 0 to 4, according to a

clinical grading system, which we described previously.18 Patients were examined and evaluated

by independent examiners at each follow-up.Kabut kornea diukur pada lampu celah dan dinilai

pada skala 0 hingga 4, menurut sistem grading klinis, yang kita dijelaskan previously.18 Pasien

diperiksa dan dievaluasi oleh pemeriksa independen pada setiap tindak lanjut.Data obtained at

the end of 10 years were evaluated and analyzed using the format for reporting refractive

surgical data.35,36 Efficacy index was defi ned as (postoperative UCVA/preoperative BSCVA)

and the safety index was defi ned as Data yang diperoleh pada akhir 10 tahun dievaluasi dan

dianalisis menggunakan format pelaporan data.35 bedah bias, 36 indeks Keberhasilan adalah defi

ned sebagai (pascaoperasi UCVA / BSCVA pra operasi) dan indeks keselamatan adalah defi ned

sebagai

(postoperative BSCVA/preoperative BSCVA).(Pascaoperasi BSCVA / BSCVA pra operasi).

STATISTICAL ANALYSISANALISIS STATISTIK

Statistical analysis was performed using SPSS for Windows, version 11.5 (SPSS Inc, Chicago,

Ill).Analisis statistik dilakukan dengan menggunakan SPSS for Windows, versi 11,5 (SPSS Inc,

Chicago, III). The differences between the two groups in categorical clinical outcomes were

assessed using chi-square tests.Perbedaan antara kedua kelompok dalam hasil klinis kategoris

dinilai menggunakan tes chi-kuadrat.Quantitative outcomes were analyzed using two-sample t

test when normality (checked using Kolmogorov - Smirnov test coupled with histograms) and

homogeneity of variance assumptions were satisfied; otherwise the non-parametric equivalent

Mann-Whitney U test was applied. Statistical signifi cance was set at P -.05.Hasil kuantitatif

dianalisis dengan uji t sampel-dua ketika normal (diperiksa menggunakan Kolmogorov -

Smirnov digabungkan dengan uji histogram) dan asumsi homogenitas varians merasa puas;

dinyatakan non-parametrik setara Mann-Whitney U test diterapkan secara signifikan. Cance

Statistik ditetapkanP-. 05.

RESULTSHASIL

VISUAL ACUITY EFFICACYVISUAL ketajaman Efikasi


18/28

18

Preoperatively, 73% of eyes (103/141) in the LASIK group had BSCVA 20/40 or better

compared to 58.8% of eyes (30/51) in the PRK group ( P=.045).Sebelum operasi, 73% dari

mata (103/141) pada kelompok LASIK telah BSCVA 20/40 atau lebih baik dibandingkan dengan

58,8% dari mata (30/51) pada kelompok PRK(P=. 045).Rerata UCVA in the LASIK group was

higher 3 months (0.46-0.18 vs 0.31-0.20, P-.01), 1 year (0.51-0.18 vs 0.38-0.19,P-.01), and 2

years (0.53-0.18 vs 0.41-0.19, P-.01) after surgery compared to the PRK group (Fig 1). Rerata

UCVA pada kelompok LASIK lebih tinggi 3 bulan (0,46-0,18 vs 0,31-0,20, P) -. 01, 1 tahun

(0,51-0,18 vs 0,38-0,19, P) -. 01, dan 2 tahun (0,53-0,18 vs 0,41-0,19, P) -. 01 setelah operasi

dibandingkan dengan kelompok PRK (Gambar 1).Rerata UCVA in the LASIK group was also

better than the PRK group at 5 and 10 years postoperatively, but the difference was not

statistically significant.Rerata UCVA pada kelompok LASIK juga lebih baik daripada kelompok

PRK pada 5 dan 10 tahun pasca operasi, tetapi perbedaannya secara statistik tidak signifikan.

Three months after surgery, the percentage of eyes in the LASIK group with UCVA of 20/40 or

better was 49.6% (69/139) compared to 23.5% (12/51) in the PRKgroup ( P -.01).Tiga bulan

setelah operasi, persentase mata di kelompok LASIK dengan UCVA dari 20/40 atau lebih baik

adalah 49,6% (69/139) dibandingkan dengan 23,5% (12/51) di PRKgroup (P -. 01). The

percentage of eyes with UCVA of 20/40 or better was higher in the LASIK group compared to

the PRK group throughout all follow-up.Persentase mata dengan UCVA dari 20/40 atau lebih

baik lebih tinggi pada kelompok LASIK dibandingkan dengan kelompok PRK seluruh tindak

lanjut. The difference was statistically signifi cant at 3 months, 1 Perbedaannya adalah cant

signifikan secara statistik pada 3 bulan, 1

year, and 2 years after surgery (Fig 2).tahun, dan 2 tahun setelah operasi (Gambar 2).

Rerata efficacy index of the PRK group was 0.65-0.38 3 months after surgery compared to 0.85-

0.35 in the LASIK group (P-.01).Berarti keberhasilan indeks dari kelompok PRK adalah 0,65-

0,38 3 bulan setelah operasi dibandingkan dengan 0,85-0,35 pada kelompok LASIK (P) -. 01.

The rerata efficacy indices of the PRK group improved to 0.80-0.38 1 year after surgery and

0.88-0.34 2 years after surgery (Fig 3).Indeks efektivitas rerata dari kelompok PRK diperbaiki

untuk 0,80-0,38 1 tahun setelah operasi dan 0,88-0,34 2 tahun setelah operasi (Gambar 3).

However, the rerata efficacy indices of the PRK group remained statistically lower compared to

the LASIK group 1 year postoperatively.Namun, indeks kemanjuran rerata dari kelompok PRK

tetap statistik lebih rendah dibandingkan dengan kelompok LASIK 1 tahun pascaoperasi. The


19/28

19

rerata efficacy indices of the PRK group continued to improve and at 5 years after surgery, the

rerata efficacy index of the PRK group was 0.94-0.40 and 0.94-0.42 for the LASIK group ( P

=.95).Indeks efektivitas rerata dari kelompok PRK terus meningkatkan dan pada 5 tahun setelah

operasi, indeks kemanjuran rerata dari kelompok PRK adalah 0,94-0,40 dan 0,94-0,42 untuk

kelompok LASIK(P=. 95).No statistical difference was noted in the rerata efficacy indices of

both groups 10 years after surgery (0.82-0.51 in the PRK group versus 0.87-0.50 in the LASIK

group,P=.51).Tidak ada perbedaan statistik tercatat dalam indeks keberhasilan rata-rata kedua

kelompok 10 tahun setelah pembedahan (0,82-0,51 pada kelompok PRK versus 0,87-0,50 di

grup LASIK,P=. 51).

STABILITY AND RETREATMENTSSTABILITAS DAN RETREATMENTS

The rerata MRSE of the PRK group showed an undercorrection of -0.91-1.76 D 3 months after

surgery, which improved to -0.51-1.38 D 1 year postoperatively (Fig 4).The MRSE rerata dari

kelompok PRK menunjukkan undercorrection dari -0.91-1.76 D 3 bulan setelah operasi, yang

ditingkatkan untuk -0.51-1.38 tahun pascaoperasi D 1 (Gambar 4).The rerata MRSE in the PRK

group was -1.81-1.79 D 10 years after surgery.The MRSE berarti pada kelompok PRK adalah -

1.81-1.79 D 10 tahun setelah operasi.The stability graph of the LASIK group shows an initial

overcorrection of 0.31-1.86 D followed by regression (see Fig 4). Grafik stabilitas kelompok

LASIK menunjukkan overcorrection awal 0,31-1,86 D diikuti dengan regresi (lihat Gambar 4).

The rerata MRSE 10 years after surgery was -1.48-1.99 D. The rerata total regression over 10

years (from 1- to 10- year follow-up) was 1.28-1.78 D in the PRK group and 1.49-2.17 D in the

LASIK group ( P=.54).The MRSE berarti 10 tahun setelah pembedahan -1.48-1.99 D. regresi

berarti total lebih dari 10 tahun (dari 1 - sampai 10 - tahun tindak lanjut) adalah 1,28-1,78 D pada

kelompok PRK dan 1,49-2,17 D di LASIK kelompok(P=. 54).

Retreatment data were available for 44 PRK eyes.penafsiran data yang tersedia untuk 44 mata

PRK. Thirteen (29.5%) eyes in the PRK group underwent one retreatment procedure and 9

(20.5%) eyes underwent two retreatment procedures during the 10-year follow-up period.Tiga

belas (29,5%) mata pada kelompok PRK menjalani satu prosedur penafsiran dan 9 (20,5%) mata

menjalani dua prosedur penafsiran selama-up-tahun mengikuti periode 10.In the LASIK group,

37 (26.2%) eyes underwent one retreatment procedure and 2 (1.4%) eyes required two

retreatment procedures. Pada kelompok LASIK, 37 (26,2%) mata menjalani satu prosedur

penafsiran dan 2 (1,4%) mata membutuhkan dua prosedur penafsiran.For PRK, 10 of 13 eyes


20/28

20


follow-up, and 1 eye between 2- and 5-year follow-up. In the LASIK group, 25 of 37 eyes


follow-up, and 6 eyes between 5- and 10-year follow-up.Untuk PRK, 10 dari 13 mata menjalani

penafsiran antara 3-bulan dan 1 tahun tindak lanjut, 2 mata antara 1 - dan 2-tahun tindak lanjut,

dan 1 mata antara 2 - 5 tahun dan tindak lanjut. Dalam kelompok LASIK, 25 dari 37 mata

menjalani penafsiran antara 3-bulan dan 1 tahun tindak lanjut, 6 mata antara 1 - dan 2-tahun

tindak lanjut, dan 6 mata antara 5 - dan 10-tahun tindak lanjut. All PRK eyes underwent

retreatment with PRK and all LASIK eyes underwent retreatment with LASIK. Semua mata

PRK menjalani penafsiran dengan PRK dan semua mata LASIK menjalani penafsiran dengan

LASIK.

PREDICTABILITY OF REFRACTIVE OUTCOMESPrediktabilitas HASIL bias

One year after surgery, 35 (68.6%) eyes in the PRK group were within -1.00 D of attempted

correction whereas 90 (63.8%) eyes from the LASIK group were within -1.00 D. Fifty-nine

percent of eyes (30 eyes) in the PRK group were within -1.00 D of emmetropia compared to

64.5% (91 eyes) in the LASIK group 2 years after surgery (Fig 5A).Satu tahun setelah operasi,

35 (68,6%) mata di kelompok PRK itu dalam -1,00 D koreksi berusaha sedangkan 90 (63,8%)

dari kelompok mata LASIK itu dalam -1,00-Lima puluh sembilan persen D. mata (30 mata)

dalam kelompok PRK itu dalam -1,00 D emmetropia dibandingkan dengan 64,5% (91 mata)

pada kelompok LASIK 2 tahun setelah operasi (Gambar 5A).These figures decreased to 41%

(21 eyes) in the PRK group and 42.5% (60 eyes) in the LASIK group 10 years after surgery (Fig

5B). Angka-angka ini menurun menjadi 41% (21 mata) pada kelompok PRK dan 42,5% (60

mata) pada kelompok LASIK 10 tahun setelah pembedahan (Gambar 5B).The proportions of

eyes with MRSE of -1.00 D or worse in both groups were higher 10 Proporsi mata dengan

MRSE dari -1,00 D atau lebih buruk pada kedua kelompok lebih tinggi 10

years after surgery compared to 2 years after surgery.tahun setelah operasi dibandingkan dengan

2 tahun setelah operasi.Thirty-three percent of eyes (17 eyes) in the PRK group had MRSE of -

1.00 D or worse 2 years after surgery compared to 57% of eyes (29 eyes) 10 years after surgery.

In the LASIK group, 15% of eyes (22 eyes) had MRSE of -1.00 D or worse 2 years after surgery

compared to 50% of eyes (71 eyes) 10 years after surgery.Tiga puluh tiga persen dari mata (17

mata) pada kelompok PRK telah MRSE dari -1,00 D atau lebih buruk 2 tahun setelah


21/28

21

pembedahan dibandingkan dengan 57% dari mata (29 mata) 10 tahun setelah operasi. Pada

kelompok LASIK, 15% dari mata (22 mata) telah MRSE dari -1,00 D atau lebih buruk 2 tahun

setelah pembedahan dibandingkan dengan 50% dari mata (71 mata) 10 tahun setelah operasi.

SAFETY AND COMPLICATIONSKESELAMATAN DAN KOMPLIKASI

The change in lines of BSCVA 10 years after surgery is summarized in Figure 6. Perubahan

baris BSCVA 10 tahun setelah pembedahan diringkas dalam Gambar 6. These data were

available for 43 PRK eyes and 117 LASIK eyes.Data-data yang tersedia untuk 43 mata PRK dan

117 mata LASIK.Six (14%) eyes from the PRK group lost 2 or more lines of BSCVA compared

to 7 (6%) eyes from the LASIK group.Enam (14%) dari kelompok mata PRK kehilangan 2 atau

lebih baris BSCVA dibandingkan 7 (6%) dari kelompok mata LASIK.Four eyes from the PRK

group lost 2 or more lines of BSCVA due to choroidal neovascular membrane formationEmpat

mata dari kelompok PRK kehilangan 2 atau lebih baris BSCVA karena pembentukan membran

neovascular choroidal

and the loss in the other 2 eyes was due to the presence of haze. dan kerugian di mata 2 lain

disebabkan adanya kabut.Two eyes from the LASIK group lost 2 or more lines of BSCVA due

to choroidal neovascular membrane formation, 1 eye to retinal detachment, and 4 eyes to cataract

formation. Dua mata dari kelompok LASIK kehilangan 2 atau lebih baris BSCVA karena

pembentukan membran neovascular choroidal, 1 mata untuk ablasi retina, dan 4 formasi mata

untuk katarak.There were no cases of cornea ectasia in either the PRK or LASIK group. Tidak

ada kasus ektasia kornea baik dalam PRK atau kelompok LASIK.

Eighteen (35.3%) eyes that underwent PRK had at least grade 1 haze 3 months after surgery.

Delapan belas (35,3%) mata yang menjalani PRK setidaknya kelas 1 kabut 3 bulan setelah

operasi.At 2 years postoperatively, 11 (21.6%) eyes were observed to have grade 1 haze. Pada 2

tahun pascaoperasi, 11 (21,6%) mata diamati memiliki kelas 1 kabut.At 10-year follow-up, 6

(11.8%) eyes were noted to have grade 1 haze.Pada tahun 10-tindak lanjut, 6 (11,8%) mata yang

tercatat memiliki kelas 1 kabut.One (16.7%) of these 6 eyes underwent two retreatments and 1

(16.7%) eye underwent only one retreatment. Satu (16,7%) dari 6 mata menjalani dua

retreatments dan 1 (16,7%) menjalani mata hanya satu penafsiran.No eye that underwent LASIK

was noted to have haze during 10-year follow-up. Tidak ada mata yang menjalani LASIK

tercatat memiliki kabut selama 10 tahun tindak lanjut.


22/28

22

The rerata safety index was calculated after excluding all eyes with cataracts or retinal pathology

(PRK: 2 cataracts, 4 choroidal neovascular membrane, and 1 retinal detachment; LASIK: 18

cataracts, 5 choroidal neovascular membrane, and 5 retinal detachments). Indeks keselamatan

dihitung rata-rata adalah setelah tidak termasuk semua mata dengan katarak atau kelainan retina

(PRK: 2 katarak, 4 membran neovascular choroidal, dan 1 ablasi retina; LASIK: 18 katarak, 5

membran neovascular choroidal, dan 5 detasemen retina). The rerata safety index of the PRK

group was lower than the LASIK group at 3 months after surgery (0.93-0.37 vs 1.11-0.35, P-

.01).Indeks keselamatan rerata dari kelompok PRK lebih rendah dari kelompok LASIK pada 3

bulan setelah operasi (0,93-0,37 vs 1,11-0,35, P) -. 01.The rerata safety indices of the LASIK

group remained higher than the PRK group at 1-, 2-, 5-, and 10-year follow-up. However, the

differences in rerata safety indices were not statistically signifi cant (Fig 7). Indeks keselamatan

rerata dari kelompok LASIK tetap lebih tinggi dibandingkan dengan kelompok PRK pada 1 -, 2 -

, 5 -, dan 10 tahun tindak lanjut. Namun, perbedaan dalam indeks keamanan berarti tidak

signifikan secara statistik cant (Gambar 7).

DISCUSSIONDISKUSI

Our study compared the 10-year refractive outcomes of eyes with high myopia ( - 10.00 D),

which had undergone LASIK or PRK at our center. Penelitian kami dibandingkan tahun-10 bias

hasil mata dengan miopia tinggi ( - 10.00 D), yang telah menjalani LASIK atau PRK di pusat

kami.Today, PRK is no longer performed for high myopia. Hari ini, PRK tidak lagi dilakukan

untuk miopia tinggi. Phakic intraocular lenses (IOLs) are also preferred over LASIK in the

treatment of high myopia and are a safer option especially if the cornea is relatively thin. Hence,

our data comparing the long-term effects of PRK and LASIK when used at the extreme limits of

excimer laser will be impossible to obtain today. Phakic lensa intraokular (IOLs) juga lebih

disukai daripada LASIK dalam pengobatan miopia tinggi dan merupakan pilihan yang lebih

aman terutama jika kornea relatif tipis. Oleh karena itu, data kami membandingkan efek jangka

panjang PRK dan LASIK bila digunakan di batas ekstrim laser excimer akan mustahil untuk

mendapatkan hari ini.Although data in the literature compare eyes that underwent LASIK versus

PRK, the number of studies comparing eyes with high myopia is lacking and the few such

studies have follow-up periods of 12 months or less.30,32,33 A meta-analysis by Shortt et al37

reported that LASIK has superior efficacy and safety compared to PRK; however, this meta

analysis involved randomized controlled studies that evaluated eyes with myopia of up to - 8.00


23/28

23

D. Meskipun data dalam literatur membandingkan mata yang menjalani LASIK versus PRK,

jumlah studi yang membandingkan mata dengan miopia tinggi kurang dan beberapa studi

tersebut memiliki tindak lanjut periode 12 bulan less.30, atau 32,33 A meta-analisis dengan

Shortt et al37 melaporkan bahwa LASIK memiliki efikasi yang superior dan keamanan

dibandingkan dengan PRK, namun analisis meta terlibat penelitian acak terkontrol yang

dievaluasi dengan mata miopia sampai - 8,00 D.

The visual acuity efficacy of PRK in eyes with high myopia in our study is lower than LASIK,

especially in the first 2 years after surgery. This is reflected in the lower rerata UCVA,

proportion of eyes with UCVA of 20/40 or better, and the rerata effi cacy index for all follow-up

examinations. Helmy et al,29 in a study comparing eyes with preoperative myopia of -6.00 to -

10.00 D that had undergone PRK and LASIK, also reported superior visual acuity effi cacy for

LASIK compared to PRK. Keberhasilan ketajaman visual PRK di mata dengan miopia yang

tinggi dalam penelitian kami lebih rendah dari LASIK, terutama pada tahun-tahun pertama 2

setelah operasi. Hal ini tercermin dalam rata-rata yang lebih rendah UCVA, proporsi mata

dengan UCVA dari 20/40 atau lebih baik, dan yang cacy indeks efisiensi berarti untuk semua-up

mengikuti ujian juga. Helmy et al, 29 dalam studi pra operasi membandingkan mata dengan

miopia dari -6,00 untuk -10,00 D yang telah menjalani PRK dan LASIK, melaporkan ketajaman

visual yang superior cacy efisiensi untuk LASIK dibandingkan PRK.One possible explanation

for the inferior results of PRK is the high incidence of haze among eyes with PRK in our study.

Satu penjelasan yang mungkin untuk hasil inferior PRK adalah tingginya insiden kabut antara

mata dengan PRK dalam penelitian kami. The proportion of eyes with haze in our study

decreased with time. Proporsi mata dengan kabut dalam penelitian kami penurunan terhadap

waktu.However, at 10-year follow-up 11.8% (6/51) of eyes still had grade 1 haze, with 2 eyes

having lost 2 or more lines of BSCVA.Namun, pada tahun 10-up 11,8% mengikuti (6 / 51) mata

masih kelas 1 kabut, dengan 2 mata kehilangan 2 atau lebih baris BSCVA.

Both the LASIK and PRK groups showed statistically similar regression over the 10-year follow-

up period. Baik LASIK dan PRK kelompok serupa regresi statistik menunjukkan selama

periode-up-tahun mengikuti 10.At 10-year follow-up, the LASIK group demonstrated a rerata

change of -1.49 D compared to the fi rst year refraction whereas the PRK group demonstrated a

rerata change of -1.28 D. An improvement in rerata MRSE towards emmetropia was noted at 1-

year follow-up compared to 3-month follow-up in the PRK group.Pada tahun 10-tindak lanjut,


24/28

24

kelompok LASIK menunjukkan perubahan rata-rata -1,49 D dibandingkan dengan tahun fi rst

refraksi sedangkan kelompok PRK menunjukkan perubahan rata-rata -1,28 D. Perbaikan MRSE

berarti terhadap emmetropia tercatat sebesar 1 tahun tindak lanjut dibandingkan dengan 3-bulan

ke dalam kelompok PRK.This is attributed to the retreatment procedures, which were mostly

performed within the first year after PRK. Hal ini disebabkan oleh prosedur penafsiran, yang

sebagian besar dilakukan dalam tahun pertama setelah PRK.The refractive predictability of both

the LASIK and PRK groups appears similar at 10-year follow-up, with 41% (21/51) of eyes in

the PRK group and 42.5% (60/141) of eyes in the LASIK group within -1.00 D of emmetropia.

Prediktabilitas bias baik LASIK dan PRK muncul kelompok serupa di tahun 10-tindak lanjut,

dengan 41% (21/51) mata pada kelompok PRK dan 42,5% (60/141) dari mata di dalam

kelompok LASIK - 1,00 D emmetropia. However, more eyes in the PRK group required

retreatment and more eyes in the PRK group required multiple retreatments, suggesting that PRK

may have a lower long-term refractive predictability in eyes with high myopia compared to

LASIK.Namun, mata lebih dalam kelompok PRK dibutuhkan penafsiran dan mata lebih dalam

kelompok PRK diperlukan beberapa retreatments, menunjukkan bahwa PRK mungkin memiliki

prediktabilitas jangka panjang bias-rendah di mata dengan miopia tinggi dibandingkan LASIK.

The long-term complications of PRK and LASIK in the treatment of high myopia have been well

described in other studies.17,18 In our study, a higher percentage of eyes in the PRK group

(14%, 6 eyes) lost more than 2 lines of BSCVA compared to the LASIK group (6%, 7 eyes). The

komplikasi jangka panjang PRK dan LASIK dalam pengobatan miopia tinggi telah baik

dijelaskan dalam studies.17 lainnya, 18 Dalam penelitian kami, persentase lebih tinggi pada

kelompok mata PRK (14%, 6 mata) kehilangan lebih dari 2 baris BSCVA dibandingkan dengan

kelompok LASIK (6%, 7 mata).However, the causes of the reduction in BSCVA in most cases

are likely to be associated with high myopia and age rather than with the procedures alone, ie,

choroidal neovascular membrane formation, retinal detachment, and cataracts. 38 - 41 In our

analysis of the rerata safety indices, after excluding cases with retinal pathology or cataracts, we

observed no statistical difference in the rerata safety indices between the LASIK and PRK

groups.Namun, penyebab pengurangan BSCVA dalam banyak kasus cenderung dikaitkan

dengan miopia tinggi dan usia daripada dengan prosedur saja, yaitu pembentukan membran

neovascular choroidal, ablasi retina, dan katarak -. 38 41 Dalam analisis kita tentang berarti

indeks keamanan, setelah tidak termasuk kasus dengan patologi retina atau katarak, kami


25/28

25

mengamati ada perbedaan statistik dalam indeks keamanan berarti antara kelompok LASIK dan

PRK.

The development of haze in postoperative PRK eyes is a direct complication of PRK, and the

incidence and severity is worse for eyes with high myopia. In our study, 2 (4.6%) eyes that

underwent PRK lost 2 or more lines of BSCVA due to haze and another 4 (9.4%) eyes were also

observed to have grade 1 haze 10 years after surgery. Perkembangan kabut di mata PRK

pascaoperasi adalah komplikasi langsung dari PRK, dan insiden dan keparahan yang lebih buruk

untuk mata dengan miopia yang tinggi. Dalam penelitian kami, 2 (4,6%) mata yang menjalani

PRK kehilangan 2 atau lebih baris BSCVA karena kabut dan lain 4 (9,4%) mata juga diamati

untuk kelas 1 kabut 10 tahun setelah operasi.This may be a compelling reason not to perform

PRK in eyes with high myopia.Hal ini mungkin merupakan alasan kuat untuk tidak melakukan

PRK di mata dengan miopia yang tinggi.Haze is a potential adverse effect seen in eyes that have

undergone PRK.Haze adalah potensi dampak buruk terlihat di mata yang telah menjalani PRK.

It can occur in any postoperative PRK eye but is more common among eyes with myopia - 6.00

D. It is also more severe in higher myopia.5 Studies have reported up to 85% haze after 24

months in eyes with myopia of - 6.00 to - 10.00 D that have undergone PRK and in 8.6% of eyes

with preoperative myopia - 6.00 D 10 years after PRK.3,18 In our study, we also noted a

reduction in the number of eyes that were observed to have haze with time. Hal ini dapat terjadi

dalam setiap mata PRK pasca operasi tapi lebih sering terjadi di antara mata dengan miopia -

6,00 D. Hal ini juga lebih parah pada tinggi myopia.5 Studi telah melaporkan sampai 85% asap

setelah 24 bulan dalam mata dengan miopia dari - 6,00 untuk - 10,00 D yang telah menjalani

PRK dan 8,6% dari mata dengan miopia preoperative - 6,00 tahun D 10 setelah PRK.3, 18

Dalam penelitian kami, kami juga mencatat penurunan jumlah mata yang diamati memiliki kabut

dengan waktu.Eighteen (35.3%) eyes were noted to have haze of at least grade 1 compared to 6

(11.8%) eyes at 10-year follow-up.Delapan belas (35,3%) mata yang tercatat memiliki paling

sedikit kabut dibandingkan kelas 1 sampai 6 (11,8%) mata pada tahun 10-tindak lanjut.This was

consistent with other studies that showed similar reduction in the incidence of haze with time.18

Although it has been suggested that the use of mitomycin C during PRK may decrease the

incidence and severity of haze,42,43 more studies are needed to confirm this finding. Ini

konsisten dengan studi lain yang menunjukkan penurunan yang serupa dalam kejadian kabut

dengan time.18 Meskipun telah disarankan bahwa penggunaan C mitomycin selama PRK dapat


26/28

26

menurunkan kejadian dan keparahan kabut, 42,43 studi lebih diperlukan untuk mengkonfirmasi

temuan ini.

High myopia is a risk factor for postoperative LASIK corneal ectasia.44 Although no eyes in our

study lost two or more lines of BSCVA due to corneal ectasia, meticulous preoperative patient

selection is required to reduce the risk of this complication. miopia tinggi merupakan faktor

risiko pascaoperasi ectasia.44 kornea mata LASIK Meskipun tidak ada dalam penelitian kami

kehilangan dua atau lebih baris BSCVA karena ektasia kornea, seleksi pasien pra operasi cermat

diperlukan untuk mengurangi risiko komplikasi ini.Treatment of high myopia requires a greater

amount of stromal ablation to correct the refractive error, resulting in a thinner residual stromal

bed, which may increase the risk of postoperative LASIK ectasia. Pengobatan miopia tinggi

memerlukan sejumlah besar ablasi stroma untuk memperbaiki kesalahan bias, sehingga dalam

sisa stroma tempat tidur tipis, yang dapat meningkatkan risiko ektasia pasca operasi LASIK.

Although the safe residual stromal bed thickness is debatable, most refractive surgeons agree that

a residual stromal bed of at least 250 m will reduce the risk of postopera tive LASIK ectasia.

Meskipun ketebalan sisa stroma tempat tidur yang aman masih bisa diperdebatkan, bias ahli

bedah yang paling setuju bahwa sisa stroma tempat tidur minimal 250 m akan mengurangi

risiko ektasia pasca operasi LASIK. Thus, it is important to measure the preoperative corneal

thickness and to calculate the residual corneal thickness. Dengan demikian, penting untuk

mengukur ketebalan kornea pra operasi dan untuk menghitung sisa ketebalan kornea.

This is a retrospective study with its associated problems, for example, missing data for some

follow up examinations, inter-observer bias, etc. One important limitation of our study is that due

to the long-term nature of our study and the rapid advancement of refractive surgery technology,

the technology and techniques used in our study are no longer in use currently. Ini merupakan

studi retrospektif dengan masalah-masalah yang terkait, misalnya, data hilang untuk beberapa

tindak lanjut pemeriksaan, bias antar-pengamat, dll Salah satu batasan penting dari studi kami

adalah bahwa karena sifat jangka panjang dari penelitian kami dan kemajuan pesat teknologi

bedah bias, teknologi dan teknik yang digunakan dalam penelitian kami tidak lagi digunakan saat

ini.Changes in technology and techniques since the study period are likely to alter our findings.

Perubahan dalam teknologi dan teknik sejak masa penelitian cenderung mengubah temuan kami.

However, as PRK is not routinely used to treat high myopia currently, a similar study would be

impossible to conduct.Namun, seperti PRK tidak secara rutin digunakan untuk mengobati


27/28

27

miopia tinggi saat ini, sebuah studi yang sama tidak mungkin untuk melakukan. With the

introduction of newer generation phakic IOLs, which are safer, LASIK is also no longer

routinely used to treat high myopia. Another important limitation is that we only have data on

patients who returned for follow-up (approximately 15% to 20%). Dengan diperkenalkannya

phakic IOLs generasi yang lebih baru, yang lebih aman, LASIK juga tidak lagi secara rutin

digunakan untuk mengobati miopia tinggi. Keterbatasan lain yang penting adalah bahwa kita

hanya memiliki data pada pasien yang kembali untuk tindak lanjut (sekitar 15% sampai 20%) .

We do not have information on why patients did not return for follow-up. Kami tidak memiliki

informasi tentang mengapa pasien tidak kembali untuk tindak lanjut. They may have had

complications such as corneal ectasia or haze or may just be satisfied patients who did not want

further follow-up. Mereka mungkin punya komplikasi seperti ektasia kornea atau kabut atau

hanya mungkin pasien puas yang tidak ingin ditindak lanjuti.

Laser in situ keratomileusis and PRK have been shown to have similar visual acuity effi cacy in

the treatment of eyes with myopia - 10.00 D in the long-term but visual rehabilitation in

postoperative PRK eyes appears to take longer compared to LASIK.Keratomileusis laser di situ

dan PRK telah terbukti memiliki ketajaman visual yang sama cacy efisiensi dalam pengobatan

mata dengan miopia - 10.00 D dalam jangka panjang tapi visual rehabilitasi pasca operasi mata

PRK tampaknya membutuhkan waktu lebih lama dibandingkan LASIK. Laser in situ

keratomileusis has also been shown to have superior visual acuity efficacy and safety over PRK

in the first 2 years after surgery. Keratomileusis laser di situ juga telah terbukti memiliki

kemanjuran ketajaman visual yang superior dan keamanan atas PRK pada tahun-tahun pertama 2

setelah operasi. However, treatment of myopia - 10.00 D by LASIK is no longer routinely

advocated whereas PRK is no longer performed due to potential complications associated with

the treatment of high myopia in both procedures.Namun, perawatan miopia - 10.00 D oleh

LASIK tidak lagi secara rutin menganjurkan bahwa PRK tidak lagi dilakukan karena komplikasi

potensial yang berkaitan dengan pengobatan miopia tinggi di kedua prosedur.Both procedures

are associated with signifi cant regression in the longterm with a higher percentage of eyes that

underwent PRK requiring at least one retreatment procedure during the 10-year follow-up.

Kedua prosedur yang terkait dengan regresi cant signifikan dalam jangka panjang dengan

persentase yang lebih tinggi dari mata yang menjalani PRK membutuhkan sedikitnya satu

penafsiran prosedur di selama 10 tahun tindak lanjut.Haze in postoperative PRK eyes with high


28/28

myopia was a signifi cant long-term problem and is an important consideration to preclude

performing PRK on eyes with high myopia. Kabut di mata PRK pascaoperasi dengan miopia

tinggi cant signifikan adalah masalah jangka panjang dan merupakan pertimbangan penting

untuk menghindari melakukan PRK pada mata dengan miopia yang tinggi.

Comparison of LASIK Translate

Documents

Transcript of Comparison of LASIK Translate